A Market Investigation for Budweiser IPA

All supporting discussion about code will be in blue italics.

library(dplyr)
library(here)
library(ggplot2)
library(tidyr)
library(ggthemes)
library(doBy)
library(reshape)
library(plotly)
library(GGally)
library(caret)
library(e1071)
library(class)
library(usmap)
library(randomForest)

First, we create some custom theme to ensure homogeneity throughout the presentation deck.

# set global theme
# custom theme
bg_color = "#0B0C10"
bar_color = "#66FCF1"
text_main = "#FFFFF"
text_ticks = "#CFC6C7"
axis_lines = #453a3b"
cust_theme <- theme(plot.title = element_text(color = 'white', vjust=0.5, hjust=0.5),
                    plot.background = element_rect(fill = bg_color),
                    panel.background = element_rect(fill = bg_color),
                    axis.text.x=element_text(angle=90,hjust=1),
                    axis.text = element_text(colour = text_ticks),
                    panel.grid.major.x = element_blank(),
                    panel.grid.minor.x = element_blank(),
                    panel.grid.major.y =  element_line(colour = "#453a3b", linetype = 1, size = 0.25),
                    panel.grid.minor.y = element_blank(),
                    axis.title = element_text(colour = "white"))

# overwrite default theme with custom
theme_set(theme_foundation() + cust_theme)

Then, we created a relative file path from the “here” library for better reproducibility. After setting our working directory, we imported the files into dataframes for better transformation capabilities.

# set relative brewery file path as variable
beers_csv <- here("project_files", "Beers.csv")
breweries_csv <- here("project_files", "Breweries.csv")

# initialize dataframes
beers <- data.frame(read.csv(beers_csv))
breweries <- data.frame(read.csv(breweries_csv))

Part 1: Counting breweries by state.

In order to investigate the number of breweries in our data set, we group everything by state and then perform a tally function in order to count total breweries. Then we plot the results as a bar chart using ggplot (and plotly).

According the dataset provided, it appears that the states with the highest craft brewery count (in order) are Colorado, California, Michigan, Oregan, and Texas. From here, we can make an initial inference that these markets are most appreciative towards craft beer and would provide a great test market for the new IPA release.

# Question 1 - How many breweries are present in each state?
per_state <- breweries %>% group_by(State) %>% tally(name="breweries_per_state") %>% arrange(desc(breweries_per_state))
fig1 <- per_state %>% ggplot(aes(x=reorder(State, breweries_per_state), y=breweries_per_state)) + geom_bar(stat="identity", fill=bar_color) + ggtitle("Total Breweries per State") + ylab("Total Breweries") + xlab("State")

ggplotly(fig1)

# this is a choropleth of breweries per state
per_state$State <- trimws(per_state$State)
per_state$hover  <- with(per_state, paste(State, '<br>', "Breweries", breweries_per_state))
fig1_2 <- plot_geo(per_state, locationmode = 'USA-states') %>%
  add_trace(
    z = ~breweries_per_state, text = ~hover, locations = ~State,
    color = ~breweries_per_state, colors = 'Purples'
  ) %>%
  colorbar(title = "Breweries Per State") %>%
  layout(
    title = 'Breweries Per State in Map<br>(Hover for breakdown)',
    geo = list(
      scope = 'usa',
      projection = list(type = 'albers usa'),
      showlakes = TRUE,
      lakecolor = toRGB('white')
    )
  )

ggplotly(fig1_2)

Part 2: Joining beer and brewery datasets.

Can we combine the data? What’s it look like? In order to join the two dataframes, we called the “merge” function and joined the two dataframes on common keys - brewery_id and brew_id. We made sure to rename the columns for easier reuse and then displayed the results using an rbind function to combine the heads and tails of the resultant dataframe.

In order to leverage our querying capabilities on the dataset, the two provided files have been joined together.

# Question 2: Merge Beer data with Breweries data. Print head(6) and tail(6)
# Note: left join breweries on beers because 1-many relationship
main <- merge(beers, breweries, by.x="Brewery_id", by.y="Brew_ID")

# clean column names for good housekeeping
main_cols <- c("brewery_id", "beer_name", "beer_id", "abv", "ibu", "beer_style", "serving_ounces", "brewery_name", "city", "state")
names(main) <- main_cols

# print head and tail of resultant data set
print(rbind(head(main, 6), tail(main, 6)))

##      brewery_id                 beer_name beer_id   abv ibu
## 1             1              Get Together    2692 0.045  50
## 2             1             Maggie's Leap    2691 0.049  26
## 3             1                Wall's End    2690 0.048  19
## 4             1                   Pumpion    2689 0.060  38
## 5             1                Stronghold    2688 0.060  25
## 6             1               Parapet ESB    2687 0.056  47
## 2405        556             Pilsner Ukiah      98 0.055  NA
## 2406        557  Heinnieweisse Weissebier      52 0.049  NA
## 2407        557           Snapperhead IPA      51 0.068  NA
## 2408        557         Moo Thunder Stout      50 0.049  NA
## 2409        557         Porkslap Pale Ale      49 0.043  NA
## 2410        558 Urban Wilderness Pale Ale      30 0.049  NA
##                               beer_style serving_ounces
## 1                           American IPA             16
## 2                     Milk / Sweet Stout             16
## 3                      English Brown Ale             16
## 4                            Pumpkin Ale             16
## 5                        American Porter             16
## 6    Extra Special / Strong Bitter (ESB)             16
## 2405                     German Pilsener             12
## 2406                          Hefeweizen             12
## 2407                        American IPA             12
## 2408                  Milk / Sweet Stout             12
## 2409             American Pale Ale (APA)             12
## 2410                    English Pale Ale             12
##                       brewery_name          city state
## 1               NorthGate Brewing    Minneapolis    MN
## 2               NorthGate Brewing    Minneapolis    MN
## 3               NorthGate Brewing    Minneapolis    MN
## 4               NorthGate Brewing    Minneapolis    MN
## 5               NorthGate Brewing    Minneapolis    MN
## 6               NorthGate Brewing    Minneapolis    MN
## 2405         Ukiah Brewing Company         Ukiah    CA
## 2406       Butternuts Beer and Ale Garrattsville    NY
## 2407       Butternuts Beer and Ale Garrattsville    NY
## 2408       Butternuts Beer and Ale Garrattsville    NY
## 2409       Butternuts Beer and Ale Garrattsville    NY
## 2410 Sleeping Lady Brewing Company     Anchorage    AK

Part 3: Addressing “NA” values.

How can we address the “NA” values? In order to get a better idea of missing data, we filtered the dataframe to only null values using “is.na” and then took the count of each column using “colSums”. You can see in the print statement below that the most influencial null value is ibu. Almost half of the ibu values are missing! In order to “massage” this into workable data, we made an assumption that the median values for each style should be fairly close to the actual values. This is due to the fact that each beer style has ranges on ibu, therefore, we know a good range of potential values which the actual could lie in.

In order to use the dataset for future statistical modeling and machine learning projects, it’s important to treat any missing values in the dataset. To do this, we will follow two common approaches:

1. remove records with null values
2. replace null values with medians from each beer style

# Part 3: Address NA values in each column
# find the NA count per column to decide next steps...you will see some missing abv and A LOT of missing ibu
print(colSums(is.na(main)))

##     brewery_id      beer_name        beer_id            abv            ibu 
##              0              0              0             62           1005 
##     beer_style serving_ounces   brewery_name           city          state 
##              0              0              0              0              0

# Preserve a version of merged dataset by removing all NAs
main_clean<-na.omit(main)

Note: Because we were supposed to use approach #1, we did not use the corrected values for any of the machine learning analysis. We just wanted to provide these details to show more depth in our approach and provide an additional method that we could have followed

You can see how by providing a median value, we were able to reduce the missing IBU values to 52 (see ibu_corr) and the missing ABV values to 0 (see abv_corr).

# based on evidence, will use median abv and ibu per beer style to fill na
main <- main %>% group_by(beer_style) %>% mutate(ibu_corr = ifelse(is.na(ibu), median(ibu, na.rm = TRUE), ibu), abv_corr = ifelse(is.na(abv), median(abv, na.rm = TRUE), abv))

# let's see how we did...you will see all abv "corrected" and ibu had over 950 values "corrected"
print(colSums(is.na(main)))

##     brewery_id      beer_name        beer_id            abv            ibu 
##              0              0              0             62           1005 
##     beer_style serving_ounces   brewery_name           city          state 
##              0              0              0              0              0 
##       ibu_corr       abv_corr 
##             52              0

We wrote the results to a csv in case we would like to reference later

# Export the no-NAs file to a new csv file
write.csv(main_clean,"./Brewery_and_Beer_Clean.csv", row.names = FALSE)

Part 4: Median ABV and IBU for entire dataset.

After checking for null values, we then compute the median ABV and IBU for the dataset to give a representation of the central values to expect among all beers. We accomplish this using a grouping statement and then dplyr’s summarise statement in order to perform a median aggregation on each column.

What ABV and IBU levels do craft beer consumers gravitate towards? Where does traditional Budweiser fall on this scale? Based on the evidence in the dataset provided, the median ABV of the craft beer for each state provided is between 4 - 6.7%. This is a fairly tight spread, suggesting that an ABV level between the median ranges would likely be suitable to consumers in all states. However, when looking at the median IBU values, there is much more spread between states. What this would suggest is that different states have different views on how bitter their beer should be (IBU level). Currenlty, traditional Budweiser resides right in the middle of the ABV range at 5% ABV, but much lower than the median IBU for all states in the dataset (12 IBU)! Therefore, the evidence suggests that craft beer consumers might prefer Budweiser if it were more bitter (greater IBU).

# Part 4: Compute Median ABV and IBU and do bar plot
medians <- main_clean %>% group_by(state) %>% summarise(median_abv = median(abv), median_ibu = median(ibu))

#Bar_Chart_Plotter

# ibu bar plot
fig2 <- medians %>% ggplot() + geom_bar(aes(x=reorder(state, -median_ibu), y=median_ibu), stat="identity", fill=bar_color) + ggtitle("Median IBU per State") +ylab("Median IBU") + xlab("State") 

# abv bar plot
fig3 <- medians %>% ggplot() + geom_bar(aes(x=reorder(state, -median_abv), y=median_abv*100), stat="identity", fill=bar_color) + ggtitle("Median ABV per State") +ylab("Median ABV") + xlab("State") + expand_limits(y=c(0, max(medians$median_abv+0.5)))

ggplotly(fig2)

ggplotly(fig3)

# Map for Median IBU per State

medians$state <- trimws(medians$state)
medians$hover  <- with(medians, paste(state, '<br>', "IBU", median_ibu))
fig2_2 <- plot_geo(medians, locationmode = 'USA-states') %>%
  add_trace(
    z = ~median_ibu, text = ~hover, locations = ~state,
    color = ~median_ibu, colors = 'Greens'
  ) %>%
  colorbar(title = "Median IBU per State") %>%
  layout(
    title = 'Median IBU per State in Map<br>(Hover for breakdown)',
    geo = list(
      scope = 'usa',
      projection = list(type = 'albers usa'),
      showlakes = TRUE,
      lakecolor = toRGB('white')
    )
  )

ggplotly(fig2_2)

# Map for Median ABV per State

medians$state <- trimws(medians$state)
medians$hover  <- with(medians, paste(state, '<br>', "ABV", median_abv))
fig3_2 <- plot_geo(medians, locationmode = 'USA-states') %>%
  add_trace(
    z = ~median_abv, text = ~hover, locations = ~state,
    color = ~median_abv, colors = 'Reds'
  ) %>%
  colorbar(title = "Median ABV per State") %>%
  layout(
    title = 'Median ABV per State in Map<br>(Hover for breakdown)',
    geo = list(
      scope = 'usa',
      projection = list(type = 'albers usa'),
      showlakes = TRUE,
      lakecolor = toRGB('white')
    )
  )

ggplotly(fig3_2)

Part 5: State with Max ABV and Max IBU.

In order to get an idea of the maximum values in the dataset, we perform a simple lookup of maximum abv and ibu for the dataset. We do this by utilizing “which” to look up the index of the max value specified. From there, we filter our dataset to only include that particular index.

What are the limits for ABV and IBU levels of craft beer? How high are consumers willing to go? Based on the evidence provided in the dataset, it appears that the maximum ABV among the craft beers is 12.8% (~2.5x Budweiser) with a maximum IBU of 138 (11.5x Budweiser).

#Part5: The State with max ABV and max IBU
#The item with max ABV
beer_MaxAbv <- main_clean[which.max(main_clean$abv),]
print(paste0("The state has maximum alcoholic beer is:", beer_MaxAbv$state, " with ABV of ", beer_MaxAbv$abv))

## [1] "The state has maximum alcoholic beer is: KY with ABV of 0.125"

#The item with max IBU
beer_MaxIbu <- main_clean[which.max(main_clean$ibu),]
print(paste0("The state has maximum bitterness beer is:", beer_MaxIbu$state, " with IBU of ", beer_MaxIbu$ibu))

## [1] "The state has maximum bitterness beer is: OR with IBU of 138"

Part 6: Summary statistics and distribution of ABV.

To get an idea of the overall statistical distribution of the abv data, we then used “summary” to return a statistical summary of the abv data and then create a histogram to show normality and spread.

Looking further into the distribution of the ABV levels of craft beers, it appears that the average ABV of craft beer is 5.97%, with a slight right skew. According to the median, 50% of craft beers are between 0-5.6% ABV and another 50% are between 5.6 and 12.8%.

#Part6: The summary statistics and distribution of the ABV
summary(main_clean$abv)

##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
## 0.02700 0.05000 0.05700 0.05991 0.06800 0.12500

fig4 <- main_clean %>% ggplot() + geom_histogram(aes(x=abv*100), fill=bar_color) + ggtitle("Distribution of ABV") + xlab("Percent ABV")

ggplotly(fig4)

Part 7: Analysis of the relationship between ABV and IBU.

Two of the most principle characteristics of beer are the ibu and abv measurements. What’s the relationship between these two? In order to test for this, we created a scatterplot of abv vs. ibu. You can see that the positive correlation between the two suggests that higher alcohol content is common among higher abv beers.

#Part7: Relationship between IBU and ABV?
#Scatterplot
fig5 <- main_clean %>% ggplot(aes(ibu, abv*100)) + geom_point(colour=bar_color, na.rm=TRUE)+geom_smooth(method=lm, se=FALSE,color="white", linetype="dashed", na.rm=TRUE) + ggtitle("ABV vs. IBU") + ylab("abv")

ggplotly(fig5)

Part 8: KNN model and Machine Learning Based on IBU and ABV.

The first steps are preparing the data by splitting and classifying accordingly.

Next, we will create an estimation model in order to classify beers (IPA vs. Non-IPA) based on their alchol and IBU levels. The method used here will be K-nearest neighbors, which will leverage classification of known beers to compare the test value to the known. This could help us in our investigation by assisting in labeling beer styles of various other samples in addition to testing if our new Budweiser IPA will meet similar ABV and IBU to the supplied IPA’s in the dataset.

#Part8: KNN used for analysis IBU and ABV relationship of IPA and Ale(no IPA)

#Form Dataset with beer style IPA 
main_IPA <- main_clean[grep("IPA",main_clean$beer_style),]
#Exclude the "Ale" part within IPA subset
main_IPA <- main_IPA[!grepl("Ale", main_IPA$beer_style),]

print(head(main_IPA))

##    brewery_id      beer_name beer_id   abv ibu
## 1           1   Get Together    2692 0.045  50
## 7           2 Citra Ass Down    2686 0.080  68
## 15          2    Rico Sauvin    2678 0.076  68
## 18          2   Pile of Face    2675 0.060  65
## 25          4 Habitus (2014)    2668 0.080 100
## 26          4          Solis    2667 0.075  85
##                        beer_style serving_ounces              brewery_name
## 1                    American IPA             16        NorthGate Brewing 
## 7  American Double / Imperial IPA             16 Against the Grain Brewery
## 15 American Double / Imperial IPA             16 Against the Grain Brewery
## 18                   American IPA             16 Against the Grain Brewery
## 25 American Double / Imperial IPA             16 Mike Hess Brewing Company
## 26                   American IPA             16 Mike Hess Brewing Company
##           city state
## 1  Minneapolis    MN
## 7   Louisville    KY
## 15  Louisville    KY
## 18  Louisville    KY
## 25   San Diego    CA
## 26   San Diego    CA

#Form Dataset with beer style Ale 
main_Ale <- main_clean[grep("Ale",main_clean$beer_style),]
#Exclude the "IPA" part within Ale subset
main_Ale <- main_Ale[!grepl("IPA", main_Ale$beer_style),]

print(head(main_Ale))

##    brewery_id        beer_name beer_id   abv ibu              beer_style
## 3           1       Wall's End    2690 0.048  19       English Brown Ale
## 4           1          Pumpion    2689 0.060  38             Pumpkin Ale
## 10          2           A Beer    2683 0.042  42 American Pale Ale (APA)
## 12          2    Flesh Gourd'n    2681 0.066  21             Pumpkin Ale
## 13          2         Sho'nuff    2680 0.040  13        Belgian Pale Ale
## 16          2 Coq de la Marche    2677 0.051  38  Saison / Farmhouse Ale
##    serving_ounces              brewery_name        city state
## 3              16        NorthGate Brewing  Minneapolis    MN
## 4              16        NorthGate Brewing  Minneapolis    MN
## 10             16 Against the Grain Brewery  Louisville    KY
## 12             16 Against the Grain Brewery  Louisville    KY
## 13             16 Against the Grain Brewery  Louisville    KY
## 16             16 Against the Grain Brewery  Louisville    KY

Next, we will plot each seperate classification by their associated parameters in order to identify correlation between ABV and IBU for each group.

#Scatterplot of IPA and Ale datasets
fig6 <- main_IPA %>% ggplot(mapping = aes(ibu, abv)) + geom_point(colour = bar_color, na.rm=TRUE)+geom_smooth(method=lm, se=FALSE, na.rm=TRUE, colour="white") + ggtitle("IPA: ABV vs. IBU")
fig7 <- main_Ale %>% ggplot(mapping = aes(ibu, abv)) + geom_point(color = bar_color, na.rm=TRUE)+geom_smooth(method=lm, se=FALSE, na.rm=TRUE, colour="white") + ggtitle("Ale: ABV vs. IBU")

ggplotly(fig6)

ggplotly(fig7)

Now, we will rejoin the two groups together to continue to the modeling phase

#Select cols in IPA and Ale datasets and set group name
#Group numbers: Ale--1, IPA--2
test_Ale <- main_Ale %>% select(ibu,abv)
test_Ale$flag = "ALE"
test_IPA <- main_IPA %>% select(ibu,abv)
test_IPA$flag = "IPA"
test_4KNN <- rbind(test_Ale, test_IPA)  #Combine two subsets into one for later classification
test_4KNN$flag <- as.factor(test_4KNN$flag)

To further help with visualizing the IBU and ABV differences between IPA and non-IPA beers, we plotted the following scatter, colored by beer classification. You can see below how there are noticeable clusters being formed between IPA and non-IPA beers with the limit being somewhere around 50 IBU.

#Plot IPA and Ale datasets together in a single scatterplot
fig7_1 <- test_4KNN %>% ggplot(mapping = aes(ibu, abv,color=test_4KNN$flag)) + geom_point(na.rm=TRUE) + geom_smooth(method=lm, se=FALSE, na.rm=TRUE, linetype="dashed") + scale_colour_manual(name="Beer Style", values=c("ALE" = "#FF652F","IPA" ="#14A76C")) + ggtitle("ABV vs. IBU by Beer Style: KNN Test")
ggplotly(fig7_1)

Next, we will split our dataset into train-split subsets. We have specified that 70% will be used as training set, and 30% will be used for testing. Additionally, the seed has been set to 123 for reproducibility.

#Divide dataset into train and test 
set.seed(123)
trainIndex = sample(seq(1:937), 650)
trainBeers = test_4KNN[trainIndex,]
testBeers = test_4KNN[-trainIndex,] 

#Train Data Visualization
fig7_2 <- trainBeers %>% ggplot(aes(x = abv,fill = flag)) + geom_histogram() + facet_grid(rows = vars(flag))
fig7_3 <- trainBeers %>% ggplot(aes(x = ibu,fill = flag)) + geom_histogram() + facet_grid(rows = vars(flag))

ggplotly(fig7_2)

ggplotly(fig7_3)

trainBeers$flag = as.factor(trainBeers$flag)
fig7_4 <- trainBeers %>% select(abv, ibu, flag) %>% ggpairs(aes(color = flag)) + ggtitle("Distribution of Ale and IPA IBU data")
ggplotly(fig7_4)

## Warning: Can only have one: highlight

Below is us actually running the KNN model. We will add commentary after running an additional function for aesethetic appeal.

##Classification Method 1: KNN
#Train the model (k=5)
classifications = knn(trainBeers[c(1,2)],testBeers[c(1,2)],trainBeers$flag, prob = TRUE, k = 5)

#The resulting confusion matrix
CM_k5 = confusionMatrix(table(testBeers[,'flag'],classifications))

Below is a function for creating an aesthetically appealing confusion matrix

draw_confusion_matrix <- function(cm) {
  
  layout(matrix(c(1,1,2)))
  par(mar=c(2,2,2,2))
  plot(c(100, 345), c(300, 450), type = "n", xlab="", ylab="", xaxt='n', yaxt='n')
  title('CONFUSION MATRIX', cex.main=2)
  
  # create the matrix 
  rect(150, 430, 240, 370, col='#66FCF1')
  text(195, 435, 'Ale', cex=1.2)
  rect(250, 430, 340, 370, col='#F7AD50')
  text(295, 435, 'IPA', cex=1.2)
  text(125, 370, 'Predicted', cex=1.3, srt=90, font=2)
  text(245, 450, 'Actual', cex=1.3, font=2)
  rect(150, 305, 240, 365, col='#F7AD50')
  rect(250, 305, 340, 365, col='#66FCF1')
  text(140, 400, 'Ale', cex=1.2, srt=90)
  text(140, 335, 'IPA', cex=1.2, srt=90)
  
  # add in the cm results 
  res <- as.numeric(cm$table)
  text(195, 400, res[1], cex=1.6, font=2, col='white')
  text(195, 335, res[2], cex=1.6, font=2, col='white')
  text(295, 400, res[3], cex=1.6, font=2, col='white')
  text(295, 335, res[4], cex=1.6, font=2, col='white')
  
  # add in the specifics 
  plot(c(100, 0), c(100, 0), type = "n", xlab="", ylab="", main = "DETAILS", xaxt='n', yaxt='n')
  text(10, 85, names(cm$byClass[1]), cex=1.2, font=2)
  text(10, 70, round(as.numeric(cm$byClass[1]), 3), cex=1.2)
  text(30, 85, names(cm$byClass[2]), cex=1.2, font=2)
  text(30, 70, round(as.numeric(cm$byClass[2]), 3), cex=1.2)
  text(50, 85, names(cm$byClass[5]), cex=1.2, font=2)
  text(50, 70, round(as.numeric(cm$byClass[5]), 3), cex=1.2)
  text(70, 85, names(cm$byClass[6]), cex=1.2, font=2)
  text(70, 70, round(as.numeric(cm$byClass[6]), 3), cex=1.2)
  text(90, 85, names(cm$byClass[7]), cex=1.2, font=2)
  text(90, 70, round(as.numeric(cm$byClass[7]), 3), cex=1.2)
  
  # add in the accuracy information 
  text(30, 35, names(cm$overall[1]), cex=1.5, font=2)
  text(30, 20, round(as.numeric(cm$overall[1]), 3), cex=1.4)
  text(70, 35, names(cm$overall[2]), cex=1.5, font=2)
  text(70, 20, round(as.numeric(cm$overall[2]), 3), cex=1.4)
} 

Below is the initial KNN training model. You will see that the model does a pretty good job at classifying between the two (definitely better than a straight guess). Additionally, it appears to perform specificity and sensitivity are very similar suggesting that the model is likely very balanced in it’s estimations.

KNN: K=5

draw_confusion_matrix(CM_k5)

Now let’s run the same model with k=10.

The above is based on k-value is five…what about k is equal to ten? You can see here that the accuracy is the same, with the increased specificity offsetting a decrease in sensitivity.

KNN: K=10

#Alternative K to train the model (k=10)
classifications_k10 = knn(trainBeers[c(1,2)],testBeers[c(1,2)],trainBeers$flag, prob = TRUE, k = 10)

#The resulting confusion matrix
CM_k10 = confusionMatrix(table(testBeers[,'flag'],classifications_k10))
draw_confusion_matrix(CM_k10)

In order to properly “tune” our hyperparameter, k, we will perform an interative loop with 100 random samples and 90 different k-values. From there, we calculate the average model accuracy in order to choose the best k-value.

##################################################################
# Loop for many k and the average of many training / test partition

set.seed(1)
iterations = 100
numks = 90
splitPerc = .7

masterAcc = matrix(nrow = iterations, ncol = numks)

for(j in 1:iterations)
{
  trainIndices = sample(1:dim(test_4KNN)[1],round(splitPerc * dim(test_4KNN)[1]))
  train = test_4KNN[trainIndices,]
  test = test_4KNN[-trainIndices,]
  for(i in 1:numks)
  {
    classifications = knn(train[,c(1,2)],test[,c(1,2)],train$flag, prob = TRUE, k = i)
    table(classifications,test$flag)
    CM = confusionMatrix(table(classifications,test$flag))
    masterAcc[j,i] = CM$overall[1]
  }
  
}

MeanAcc = colMeans(masterAcc)

plot(seq(1,numks,1),MeanAcc, type = "l")

k_opt <- which.max(MeanAcc)
max_acc <- round(max(MeanAcc),4)*100

Based on 100 random samples and 90 different hyperparameter values, our model is capable of up to 85.7% accuracy using the 5 closest points on the scatter plot for classification. This will be a very good way to test whether the new Budweiser IPA meets the requirements for what’s considered an IPA by the craft beer market. How about other popular methods? Let’s try some different models to see if any have any significantly better results.

# now let's do some comparison with other machine learning methods
## Classification Method 2: Naive Bayes
classifications_nb = naiveBayes(trainBeers[,c(1,2)],as.factor(trainBeers$flag))
CM_nb = confusionMatrix(table(predict(classifications_nb,testBeers[,c(1,2)]),as.factor(testBeers$flag)))
draw_confusion_matrix(CM_nb)

## Classification Method 3: SVM
classifications_svm = svm(trainBeers[,c(1,2)],as.factor(trainBeers$flag))
CM_svm = confusionMatrix(table(predict(classifications_svm,testBeers[,c(1,2)]),testBeers$flag))
draw_confusion_matrix(CM_svm)

## Classification Method 4: RandomForest
classifications_rf = randomForest(trainBeers[,c(1,2)],as.factor(trainBeers$flag),ntree=500)
CM_rf = confusionMatrix(table(predict(classifications_rf,testBeers[,c(1,2)]),testBeers$flag))
draw_confusion_matrix(CM_rf)

Part 9: IPA per 100k population (additional exploration).

Initially, we will use the grep function to tally only IPA values and then filter our dataset accordingly.

# Part 9: Additional Data Exploration
# Plan - to count % IPA per total craft beers in each state.

# finding the beers containing "IPA" in their style and tallying
cat_freq <- main %>% mutate(category=
  case_when(
    grepl("IPA", beer_style) ~ "IPA",
    TRUE ~ "OTHER"
  )
) %>% group_by(state, category) %>% summarise(n=n()) %>% mutate(freq = n/sum(n)) %>% filter(category=="IPA")
cat_freq$state <- trimws(cat_freq$state)

# adding full state names from merging with us_map() library function
cat_freq <- merge(distinct(us_map(), full, abbr), cat_freq, by.x="abbr", by.y="state", all.x=TRUE) %>% mutate(n=replace_na(n, 0), freq=replace_na(freq, 0))

Next, let’s calculate our relative frequency of IPA to total craft beers per state.

# create percentage from frequency
cat_freq$freq = round(cat_freq$freq, digits=4)*100

After realizing the impact of population on market potential, I downloaded the 2019 consensus data in order to perform a “correction” for state population. My goal was to the best balance of IPA count per 100k consumers in order to find the best markets to perform trials before scaling to mass production.

# creatig dataframe from state consensus
state_pop <- data.frame(read.csv(here("project_files", "2019 consensus data.csv")))

# merging dataframe with %IPA per state dataframe
normalized_IPA <- merge(state_pop, cat_freq, by.x="State", by.y="full")

# normalizing IPA count per 100k state population
normalized_IPA <- normalized_IPA %>% mutate(IPA_per_100k = n/(Pop / 100000)) %>% arrange(desc(IPA_per_100k))

# creating a hover tag for the map
normalized_IPA$hover <- with(normalized_IPA, paste(State, '<br>', "IPA Beers", n, "<br>","IPA % of total craft beers", freq,"%", "<br>", "Population Rank", rank, "<br>", "IPA per 100k", IPA_per_100k))

Based on my calculations, you’ll see the following states are the best individual candidates for a trial run of Budeweiser IPA, according to 2019 state population and IPA interest.

# displaying a table of top 5 markets for reference
fig8 <- normalized_IPA %>% select(State, Pop, IPA_per_100k) %>% top_n(8)
fig8 %>% plot_ly(type='table',
                      header = list(
                        values = c("State", sprintf("State Population (%s Sample Size)",sum(fig8$Pop)), "IPA per 100k People")),
                      cells=list(
                        values=t(unname(as.matrix(fig8))),
                        font = list(color = c('#506784'), size = 12)
                      ))

# displaying all US IPA markets on map
fig9 <- plot_geo(normalized_IPA, locationmode = 'USA-states') %>%
  add_trace(
    z = ~IPA_per_100k, text=~hover, locations = ~abbr,
    color = ~IPA_per_100k,
    marker = list(line = list(color = toRGB(bg_color), width = 2.25)),colorscale='MAGMA'
  ) %>%
  colorbar(title = "IPA") %>%
  layout(
    title = 'IPA count per 100k',
    font = list(color = 'white'),
    geo=list(
      scope = 'usa',
      projection = list(type = 'albers usa'),
      showlakes = FALSE,
      bgcolor=toRGB(bg_color, alpha = 1)),
    paper_bgcolor=toRGB(bg_color, alpha = 1),
    margin=list(l=20, r=20, t=60, b=20)
  )

fig9